Omeprazole: an exploration of its reported genotoxicity.

Because of its reported ability to induce unscheduled DNA synthesis in the gastric mucosa, the safety of omeprazole, a potentially clinically useful anti-ulcer drug, has been the subject of debate. We have undertaken a detailed computer-based study of structural basis of the putative mutagenicity, genotoxicity and carcinogenicity in rodents of omeprazole and of its sulphenimide, and we conclude that omeprazole is a potential 'genotoxic' carcinogen. The analysis is consistent with the possibility that these activities are associated with the unstable sulphenimide metabolite.